package com.lanlian.commonlib.util;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Environment;
import android.os.Looper;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.widget.Toast;

import com.lanlian.commonlib.BaseApplication;
import com.lanlian.utillib.DateUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.Field;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

public class CrashHandler implements Thread.UncaughtExceptionHandler {

    public static final String TAG = "CrashHandler";

    // 系统默认的UncaughtException处理类
    private Thread.UncaughtExceptionHandler mDefaultHandler;
    // CrashHandler实例
    private static CrashHandler INSTANCE = new CrashHandler();
    // 程序的Context对象
    private Context mContext;
    // 用来存储设备信息和异常信息
    private Map<String, String> infos = new HashMap<>();

    public static String CRASH_SAVE_PATH = null;

    private CrashHandler() {
    }

    /**
     * 获取CrashHandler实例 ,单例模式
     */
    public static CrashHandler getInstance() {
        return INSTANCE;
    }

    /**
     * 初始化
     */
    public void init(Context context) {
        mContext = context;
        // 获取系统默认的UncaughtException处理器
        mDefaultHandler = Thread.getDefaultUncaughtExceptionHandler();
        // 设置该CrashHandler为程序的默认处理器
        Thread.setDefaultUncaughtExceptionHandler(this);
        CRASH_SAVE_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator +
                context.getPackageName() + "/crash" + File.separator;
        File dir = new File(CRASH_SAVE_PATH);
        if (!dir.exists()) {
            dir.mkdirs();
        }
    }

    /**
     * 当UncaughtException发生时会转入该函数来处理
     */
    @Override
    public void uncaughtException(Thread thread, Throwable ex) {
        handleException(ex);
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            Log.e(TAG, "error : ", e);
        }
        // 退出程序
        BaseApplication.getInstance().exitApp();
    }

    /**
     * 自定义错误处理,收集错误信息 发送错误报告等操作均在此完成.
     */
    private void handleException(Throwable ex) {
        // 使用Toast来显示异常信息
        new Thread() {
            @Override
            public void run() {
                Looper.prepare();
                Toast.makeText(mContext, "很抱歉,程序出现异常即将退出.", Toast.LENGTH_SHORT).show();
                Looper.loop();
            }
        }.start();
        // 收集设备参数信息
        if (ContextCompat.checkSelfPermission(mContext, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_GRANTED) {
            collectDeviceInfo(mContext);
            // 保存日志文件
            saveCrashInfo2File(ex);
        }
    }

    /**
     * 收集设备参数信息
     *
     * @param ctx 上下文
     */
    private void collectDeviceInfo(Context ctx) {
        try {
            PackageManager pm = ctx.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(ctx.getPackageName(), PackageManager.GET_ACTIVITIES);
            if (pi != null) {
                String versionName = pi.versionName == null ? "null" : pi.versionName;
                String versionCode = pi.versionCode + "";
                infos.put("versionName", versionName);
                infos.put("versionCode", versionCode);
            }
        } catch (PackageManager.NameNotFoundException e) {
            Log.e(TAG, "an error occured when collect package info", e);
        }
        Field[] fields = Build.class.getDeclaredFields();
        for (Field field : fields) {
            try {
                field.setAccessible(true);
                infos.put(field.getName(), field.get(null).toString());
                Log.d(TAG, field.getName() + " : " + field.get(null));
            } catch (Exception e) {
                Log.e(TAG, "an error occured when collect crash info", e);
            }
        }
    }

    /**
     * 保存错误信息到文件中
     *
     * @param ex 异常信息
     * @return 返回文件名称, 便于将文件传送到服务器
     */
    private String saveCrashInfo2File(Throwable ex) {
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, String> entry : infos.entrySet()) {
            String key = entry.getKey();
            String value = entry.getValue();
            sb.append(key).append("=").append(value).append("\n");
        }

        Writer writer = new StringWriter();
        PrintWriter printWriter = new PrintWriter(writer);
        ex.printStackTrace(printWriter);
        Throwable cause = ex.getCause();
        while (cause != null) {
            cause.printStackTrace(printWriter);
            cause = cause.getCause();
        }
        printWriter.close();
        String result = writer.toString();
        sb.append(result);
        LogUtils.e(TAG, sb.toString());
        try {
            String time = DateUtils.DateToString(new Date(), "yyyy-MM-dd HH:mm:ss SSS");
            String fileName = time + ".txt";
            if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
                File dir = new File(CRASH_SAVE_PATH);
                if (!dir.exists()) {
                    dir.mkdirs();
                }
                FileOutputStream fos = new FileOutputStream(CRASH_SAVE_PATH + fileName);
                fos.write(sb.toString().getBytes("UTF-8"));
                fos.close();
            }
            return fileName;
        } catch (Exception e) {
            Log.e(TAG, "an error occured while writing file...", e);
        }
        return null;
    }
}